Method for preparing blue coloring materials.



v of blue coloring materials and UNITED STATES PATENT OFFICE.

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Ho Drawing.

To all whom it may concern c it known that I, RAYMOND VIDAL, chemist. a citizen of the Republic of France, and resident of 10: Rue de la Comets, As- 5 nieres, Seine, Republic of France, have invented an Improved Method for Preparing Blue Coloring Materials, of which the following is a specification.

This invention refers to the preparation it consists in two operations, first: heating aramido henol or the corres ending ami ocresols in a medium formed y organic compounds *to the boiling oint in order to obtain a nonsulfureted blue colorin material; and second: transformation of the coloring mate rial So obtained into a material by introducing sulfur in the medium in which the reaction'takes place.

The organic compounds available for use in this process are the following: phenols, cresols, xylenols; either single or mixed, anilin. toluidins, xylidins.

.7 Example: In aclosed apparatus so constructed that the vapors produced flow back to it after condensation, I-introduce 11 kilograms of paramidophenol and 5 kgs, 500 grams of the commercial mixture of the three cresols. The whole is then heatedand 90 maintained in ebullition during the time,

necessary to the formation of the first, non sulfureted blue coloring material, 11. e., about 5 to 6 hours. A sample taken out of the apparatus at that moment must dissolve bright blue in alkalies. At this moment 2 kgs. 750 grams of pulverized sulfur are introduced in the apparatus and heating is continued and ebullition maintained until the escape ofhydrogen sulfid which takes place seems to stop.

he excess of organic compound is then collected either by simple distillation or by distillation in the vacuum, ,is talren out of the apparatus.

Said mass is afterward urified by wash- F ing in hot water. It has t e appearance of a thick tar which becomes solid when 0901- p n the foregoin example the'paramidoso phenol can befrep aced by one o the corresponding ainidophenols and instead ofthe V Specification or Letters Patent.

Application filed August 18, 1918. Serial No. 115,577. I

sulfureted coloring and the mass Patented Maj/1,4, 191B;

cresols I may use any one of the ebony named organic compounds, to be understood that the appended claims are to be interpreted as covering theequivm l lents stated in this description.-

The amidocresols em loyedin -thjs case can be used in the mixed state.

he coloring materials thus obtained are soluble in iilkalies to which there are added :or not alkaline hydrosulfites, and in sodiuin sulfid. In this state they dye directly vegetable fibers in indigo blue shades which resist acids and chlonn. Owing to these qualities they difl"er from the known sulfur colea oring materials and especially from the blue obtained by the direct fusion of the paramidophenol with sulfur which latter blue is not capable of resisting either acids or chlorin.

Havin now described and ascertainedthe nature of my invention and in what manner the same is to be performed, I declare that what I claim is:

1. The herein described process which vconsists in first boiling paramidophenol and cresol until a sample of the product dissolves bright blue in alkalies, the sulfur, and continuin to boil until the evoa, lut'ion of hydrogen su d appears to/sto 2. The herein described process w ich consists in first boiling aramidophenol and cresol, while returning a condensed vapors to return to the boilingmass, until a sample of the product dissolves bright blue'in alkalies, and then adding sulfa ".to the mass and continuing ttfiimil until evolution of hydro en appears to stop;

e herein described cplorin material produced by the boiling of and cresol first alone and so uently with sulfur, said material bein solu 1c in alkalies, in sodium sulfid, an in a mixture of alkalies with alkaline hydrosulfites, said material dyeinlg vegetable fibers directly in' in- 95 di 0 blue s ades resistant to acids and to ch orin. I

RAYMOND .YIDAL. Witnesses: V

- SENT; Zoo Bonner,

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and I desire aremidophenol i 

